I also have the error code E90

This answer was posted by one of the experts on here. I found it for you :)

E90 appears to be caused by faulty connectors to the main circuit board which appears in the bottom right corner, if you're looking at the washer from the front with the lid off (looking down into washer). This is fixed by reseating, cleaning the connectors.

remove 2 screws at the back which secure the top,
push the top backwards,
unplug the connectors to the front panel,
vibrations due to unbalanced load may have loosened them,
push them firmly back in socket,
pushed the top (back to front, make sure a plastic tab seats properly to secure front part of top panel) in place and fastened the screws,
power on,
run the machine empty for minimum cycle - rinse only.

Good luck!!!!

Error code bosch model:sms65n02ev